Somatostatin analogues

Abstract

The polypeptides, <IMAGE> +TR <IMAGE> the linear precursor intermediates therefor or non-toxic acid addition salts thereof in which X2 is NH2, Ala-Gly-, Ala-D-Ala-, Gly-Gly-Gly-, lower alkanoyl or benzoyl; X4 is Arg, His, D-Arg or D-His; X5 is His, Tyr, Glu, D-His, D-Tyr or D-Glu; X7 is Trp, Tyr, Met or His; and X8 is Trp or D-Trp; inhibit the release of growth hormone and are useful in the treatment of acromegaly and diabetes.

What is claimed is: 
     
       1. A compound of the formula: ##STR3## its linear precursor intermediates or non-toxic acid addition salts thereof in which X 2  is NH 2 , Ala-Gly-, Ala-D-Ala, Gly-Gly-Gly-, lower alkanoyl or benzoyl;   X 4  is Arg, His, D-Arg, or D-His;   X 5  is His, Tyr, Glu, D-His, D-Tyr, or D-Glu;   X 7  is Trp, Tyr, Met, or His; and     X 8  is Trp or D-Trp.   
     
     
       2. The compound of claim 1 in which X 7  is Trp or His. 
     
     
       3. The compound of claim 1 which is [des-Ala 1  -Gly 2  ], Arg 4 , His 5 , His 7 , D-Trp 8  -somatostatin. 
     
     
       4. The compound of claim 1 which is [des-Ala 1  -Gly 2  ], Arg 4 , His 5 , Trp 7 , D-Trp 8  -somatostatin.